<template>
  <view>
    <!-- 使用自定义的搜索组件 -->
    <!-- <my-search bgcolor="pink" :radius="3"></my-search> -->
    <my-search @click="gotoSearch"></my-search>

    <view class="scroll-view-container">
      <!-- 左侧滑动区域 -->
      <scroll-view class="left-scroll-view" scroll-y :style="{ height: wh + 'px' }">
        <block v-for="(item, i) in cateList" :key="i">
          <view
            :class="['left-scroll-view-item', i === active ? 'active' : '']"
            @click="activeChanged(i)"
          >
            {{ item.cat_name }}
          </view>
        </block>
      </scroll-view>
      <!-- 右侧滑动区域 -->
      <scroll-view
        class="right-scroll-view"
        scroll-y
        :style="{ height: wh + 'px' }"
        :scroll-top="scrollTop"
      >
        <view class="cate-lv2" v-for="(item2, i2) in cateLevel2" :key="i2">
          <!-- 二级分类的标题 -->
          <view class="cate-lv2-title">/ {{ item2.cat_name }} /</view>
          <!-- 当前二级分类下的三级分类列表 -->
          <view class="cate-lv3-list">
            <!-- 三级分类的 item 项 -->
            <view
              class="cate-lv3-item"
              v-for="(item3, i3) in item2.children"
              :key="i3"
              @click="gotoGoodsList(item3)"
            >
              <!-- 图片 -->
              <image :src="item3.cat_icon"></image>
              <!-- 文本 -->
              <text>{{ item3.cat_name }}</text>
            </view>
          </view>
        </view>
      </scroll-view>
    </view>
  </view>
</template>

<script>
import badgeMix from '@/mixins/tabbar-badge.js'

export default {
  mixins: [badgeMix],
  data() {
    return {
      // 当前设备可用的高度
      wh: 0,
      // 分类列表数据
      cateList: [],
      // 当前激活选项
      active: 0,
      // 二级分类列表
      cateLevel2: [],
      scrollTop: 0
    }
  },
  onLoad() {
    // 获取当前设备信息
    const sysInfo = uni.getSystemInfoSync()
    this.wh = sysInfo.windowHeight - 50
    // 调用获取分类列表数据的方法
    this.getCateList()
  },
  methods: {
    // 获取分类列表数据
    async getCateList() {
      const { data: res } = await uni.$http.get('/categories')
      if (res.meta.status !== 200) return uni.$showMsg()
      this.cateList = res.message

      // 为二级分类赋值
      this.cateLevel2 = res.message[0].children
    },
    // 控制激活项的切换
    activeChanged(i) {
      this.active = i

      // 重新为二级分类赋值
      this.cateLevel2 = this.cateList[i].children

      this.scrollTop = this.scrollTop === 0 ? 1 : 0
    },
    // 跳转到商品列表页面
    gotoGoodsList(item) {
      uni.navigateTo({
        url: '/subpkg/goods_list/goods_list?cid=' + item.cat_id
      })
    },
    gotoSearch() {
      uni.navigateTo({
        url: '/subpkg/search/search'
      })
    }
  }
}
</script>

<style lang="scss">
.scroll-view-container {
  display: flex;

  .left-scroll-view {
    width: 120px;

    .left-scroll-view-item {
      background-color: #f7f7f7;
      line-height: 60px;
      text-align: center;
      font-size: 12px;

      &.active {
        position: relative;
        background-color: #ffffff;

        &::before {
          position: absolute;
          top: 50%;
          left: 0;
          transform: translateY(-50%);
          content: '';
          display: block;
          width: 3px;
          height: 30px;
          background-color: #c00000;
        }
      }
    }
  }
}

.cate-lv2-title {
  font-size: 12px;
  font-weight: bold;
  text-align: center;
  padding: 15px 0;
}

.cate-lv3-list {
  display: flex;
  flex-wrap: wrap;

  .cate-lv3-item {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 33.33%;
    margin-bottom: 10px;

    image {
      width: 60px;
      height: 60px;
    }

    text {
      font-size: 12px;
    }
  }
}
</style>
